Radio receiving set



Nov. a, 1927. i 1,648,521

A.y wlKsTRoM RADIO RECEIVING -SET Filled Nov. 10, 1924 ities-zi 'Partnr lorifice.

llenan wrirs'raorr, or Boeren, ivrassnonusnfrrs, Asistencia PORATI'ON, 0F BOSTON, MASSACHUSETTS, ACORPQRATEN v0]'3 MASSCHUSETTS.

RADIO RECEIVING SET.A

Application filed November 10, 19,24. rSerial No. 748337. i l

vThis invention relates to radio receiving sets,l and more particularly to a set employing a crystal detector and equipped with means for tuning the same, all Withina relay tively small compass and contained in a case of vest-pocket dimension. A principal object of the invention is to provide an exceptionallyl simple, inexpensive but elicient set in which the tuning coil is wound upon a .block of insulating material having a bore in which the crystal detector is located to be supported by said block and to be movable with the tuningcoil into and out of a rela tively flattened case, having heads, through one .of which is extended a slider carrying a contact member which engages the ytuning coil Within the case. l

VThe foregoing and other objects and ad` vantages of the invention will more fully appear-from the following detailed descrip,-

tion ta-ken in connection with the accompanying'drawings, and thedistinctive features of novelty will be pointed out in the appended claims. v v A Referring to the drawings: Figure lis a cent-ral longitudinal section of a receiving set embodying the invention; and

Fig. 2 is a transverse Section on line2-2 ofFig. 1. y

indicates the inclosing case of the set which may be produced of hard fibre about -g inch in thickness of generally oblong cross section, preferably with flattened longer side portions 10a and rounded shorter side portions 10". The ends of the casing thus formed are closed by fibre plates or heads 11, 12 respectively, which may be 0f hard fibre of approximately-the same thickness as the body 10. I provide a block 13 which may be either of wood, hard fibre or other suitable insulating material, of a length slightly less than the longitudinal dimension of the case 10 and of a generally oval or elliptical form in cross section adapted to fit between the longer sides 10a of the case and terminating some distance short of the rounded shorter sides 10b as seen in Fig. 2. This block is wound throughout its length spirally with wire 14: to constitute the tuning coil, this wire being preferably about No. 30 gage which adapts the device to receive from one hundred to six hundred metres. The block 13 has a central bore 15 in which is fitted a crystal detector device 1G. This crystal de-A tector device may, within the contemplation i of the invention, be of any suitable type, but

preferably, and as herein .e shown, this detector device comprises a cylindrical fibre shell 17 having rfibre blocks 18, 19 fixed in the respective end portions thereof, with a crystal detector element 2()k pressed` into, and,

seated in, a body of silverwool 21which rests against the block 19 and engagesacon-V ductive head 22vborue by apstem 23 which extends through the block 19V and outward through a bore 24 of the block 13 large enough to provide clearance therefor. The. outer vextremity 25a of this stem engagesa'- contact strip 25 fixed tothe endplate 12 by means ofl a clampingbolt 26. This strip 25 has abent spring extremity 39 adapted to.

pressA against, and `make electrical lcontact 'ro FLASH' Ramo con#k with. a sliding rod 34 to be later described...k

28 indicates an adjustable spiral spring conf v tact engaging the crystal 20, this spring be ing borne by a stem 29 fitted to Vturn in the block 18.- The outer end of this Istem ex-y tending through the casing cover .plate 11v bears a relatively large dial 30 by which the spring contact 28 may beengaged withdifferent portions ofthe upper surface of the crystal. Thespring contact`28 preferably has its extremitywhich engages the crystal formed as a loop28 'A conductive strip 31Y has one end thereof in contact withthe'stem 29 and has its othery end extending underneath a telephone plug aperture 82 adjacenty one :edge of the casing covervplate 1-1, the

.portion of said strip underneath said aperture constituting a flat spring'extre'mity 31h The telephone plug hole 32 is slightly larger than the telephone plug tip P, so that said tip is adapted to be pressed through said hole into contact with the spring extremity 31a as shown. The other telephone plug aperture 32 is also slightly larger than the telephoneplug tip P and this tip, when it is pressed through said hole, engages a spring extremity 33EL of a conductive strip 33' which is in contact withone end of the tuning coil 14. This strip 33, and hence the end of thev tuning coilll- Iwith which it is connected, is engaged by, and electrically connected with, a `conductor 27 leading outward through the cover 12 to the ground connection. At opposite sides of the tuning coil within the casing, rods 34, 35 respectively are mounted for sliding movement, these 'rods being guided through apertures 36, 87

llU

' turbanceol` the crystal by vibration or blows.

respectively provided therefor in the cover` plate l2 and having` their extremities which project outward from the cover l2 equipped with knurled heads 38 constituting linger pieces. The rod 34 is electrically connected through the contact 39 With the crystal 20 and the rod 35 is similarly connected through a spring contact strip 40 with the antenna connection 41 which leads outward through.

the cover 12. The inner end of each of the rods 34, 35L is equipped with a spring contact strip 42 adaptedA to press against the" quired extent, thesecondary detector and telephone circuit is tuned, whileby sliding the rod `35 the antenna circuit is correspondingly tuned.` Thev ends of the casing may be closed2 tightly against tl'ie'entrance of dirt and moisture= by cover caps 45, 46 as indi cated in dotted lines. It will be observed that the block Il upon which the tuning coil is wound is solid and" is provided with a bore into which the crystal detector is fitted soY as to be movable into. and out of the case 101` asV a unit, which construction not only reduces the cost or the. apparatus but also lends to the eiliciency of the saine, as 'the block aii'ordsa irin. support for the crystal detector and reduces the liability of dis- I am aware'fthat the invention may be embodied in other specific forms without departing from thespirit 0r essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive,reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having described my invention, what I .Y

claim as new and Patent is:

l. In a. radio receiving set, in combination, a casing of insulating material prodesire tosecure by Letters lvided at `its oppositeends with heads, a tu-ning coil within said casing and having a solid core of insulating material vprovided with bore extended axially from oneend i thereof' and providing a housing for a crystalI detector, saidcrysta-l detector located in said bore and movable into and out of saifd casing with the tuning coil as a unit,`

and a sliderA provided with a contact member co-operating with the tuning coil.

In a radio receiving set, in combination,

a casing provided with heads at its oppositeV i ends, a tuning coil located in saidcasingand` oi suclr size and shape as to leave ar space between it and a wall of said casing, and a coil and with a bearing' member the casing to maintain'the contact member in iirni `engagement with'the tuning coil as the slider is moved .into and out of said'` space through said head.

Ina crystal radio receiving set, in com"- bination, a casing'provided at its opposite ends with heads, a tuning coil Within said.`

casing,l and a' slider extended through one of said heads andmovable. into and; out of said casing substantially the length of the|` tuningcoil and' provided within the" casing with a contact member co-operating with` said timing coil.

In testimony whereoLI have' ,signed myV naine" to this specification.

Vactivan wiKsTiioM. Y 

